How to maximize CPU usage

Question

I wrote some program that doind a longtime calculations.
When i open a task manager, i see that my exe uses only 2% of CPU.

How shoult i write my code in c# to obtain a maximum CPU time to speed up my calculation?

I try to start a several copies of my exe, but overal load was still about 5%,ive spotted that all exe eat about 0.5% cpu.
Looks like a system has some upper limit and divide time between my exe.
Is there any cpu thing in .net that try to save system from overload?
I try to find out where is a problem, in my code, in CLR, in windows or in somwhere else.

I downloaded a WinRAR archiver and start a build-in benchmark. While benchmarking it eat 90% of CPU time. So i am sure my windows is ok. Problem is in my code or in dotnet security featureas, if they presents.

No multithreading in code.
Windows server 2019

Answer 1

You should be able to use the profiling tools in Visual Studio to monitor performance.

https://learn.microsoft.com/en-us/visualstudio/profiling/?view=vs-2019

Another option is to use Sysinternals Process Monitor and trace your program to see if if is making redundant file I/O or registry calls.

https://learn.microsoft.com/en-us/visualstudio/profiling/?view=vs-2019

How many cores does your server have? A single threaded app can only use 100% of one cpu. So if you have 2 cpu's your program will use 50%. 4 cores will show 25%, etc.

In the Details tab in Task Manager, add a column for Page Faults Delta. See if it's doing something with memory (file cache).